Dry cough when it rains may be caused by allergic cough, acute upper respiratory tract infection, bronchial asthma and other factors. 1. Allergic cough: If the patient is sensitive to cold air, humid environment, smoke, dust and other factors, the respiratory tract will be easily stimulated by these factors in rainy weather, which will lead to allergic cough and the symptoms of dry cough. 2. Acute upper respiratory tract infection: It is easy to get cold on rainy days, which leads to lower immunity and susceptibility to viral infections, resulting in upper respiratory tract infections. After the upper respiratory tract infection, the mucous membrane of the respiratory tract is stimulated by inflammation, the mucous membrane is congested and edematous, which leads to the symptoms of dry cough. 3. Bronchial asthma: when it rains, the temperature is low and the air is relatively humid, so there may be some allergic or irritating bacteria, which can easily trigger bronchial asthma, resulting in dry cough symptoms. The above symptoms can also be seen in chronic obstructive pulmonary disease, nasal secretion reflux stimulation cough, gastroesophageal reflux stimulation cough and other diseases, it is recommended to go to the hospital in a timely manner, to identify the cause of the disease, and then targeted treatment, so as not to delay the condition.